Brian L Erstad

PMID: 9758312;Abstract:

Thromboembolic complications are frequent in patients with multiple trauma. The efficacy of unfractionated heparin for venous thrombosis prophylaxis has not been established. Based on limited prospective data, low- molecular-weight heparin appears to be more effective than unfractionated heparin and at least as effective as compression devices for preventing thromboembolic complications in these patients. Vena cava filters should be considered in high-risk patients who cannot receive anticoagulant therapy, but long-term filter use without concomitant anticoagulant therapy is associated with a substantial risk of recurrent thromboembolism.

PMID: 2337037;Abstract:

Amiodarone has been reported to increase phenytoin levels. This study was designed to evaluate the pharmacokinetic basis of this interaction at steady-state. Pharmacokinetic parameters for phenytoin were determined after 14 days of oral phenytoin, 2 to 4 mg/kg/day, before and after oral amiodarone, 200 mg dairy for 6 weeks in 7 healthy male subjects. During amiodarone therapy, area under the serum concentration time curve for phenytoin was increased from 208 ± 82.8 (mean ± standard deviation) to 292 ± 108 mg · hr/liter (p = 0.015). Both the maximum and 24-hour phenytoin concentrations were increased from 10.75 ± 3.75 and 6.67 ± 3.51 μg/ml to 14.26 ± 3.97 (p = 0.016) and 10.27 ± 4.67 μg/ml (p = 0.012), respectively, during concomitant amiodarone treatment. Amiodarone caused a decrease in the oral clearance of phenytoin from 1.29 ± 0.30 to 0.93 ± 0.25 liters/ hr (p = 0.002). These results were due to a reduction in phenytoin metabolism by amiodarone as evidenced by a decrease in the urinary excretion of the principal metabolite of phenytoin, 5-(p-hydroxyphenyl)-5-phenylhydantoin, 149 ± 39.7 to 99.3 ± 40.0 mg (p = 0.041) and no change in the unbound fraction of the total phenytoin concentration expressed as a percentage, 10.3 ± 2.7 versus 10.7 ± 2.1% (p = 0.28) during coadministration of amiodarone. The alterations in phenytoin pharmacokinetics suggest that steady-state doses of phenytoin of 2 to 4 mg/kg/day should be reduced at least 25% when amiodarone is concurrently administered. All dosage reductions should be guided by clinical and therapeutic drug monitoring. © 1990.

Abstract:

Objectives: The primary purpose of this pilot study was to help justify the positions of clinical pharmacists by identifying and describing the interventions most likely to have the greatest impact on patient care in terms of severity of medication-related problems and associated costs. A secondary objective was to identify potential problems related to data collection and cost estimation, to allow appropriate changes in documentation procedures for future data collection. Methods: All clinical interventions by staff pharmacists reported at a university medical centre during the period September to November 2001 were analyzed retrospectively. The focus was on interventions that prevented adverse drug events (described as very serious and serious on documentation forms). The cost impact was analyzed in terms of cost savings attained by shortening a planned course of drug therapy and cost avoidance achieved by avoiding adverse drug events. Results: Five pharmacists reported a total of 47 interventions. Approximately twice as many of the avoided adverse drug events were deemed serious as were deemed very serious. A substantial proportion of the interventions (21 [45%]) took approximately 15 to 30 min to perform. Order clarification and corrections and provision of drug information accounted for the most interventions (17 [36%] and 15 [32%], respectively). Approximately 60% of all interventions were classified as subtherapeutic dosing (10 [21%]), untreated disease states (6 [13%]), potential overdose (6 [13%]), and failure to receive drug (5 [11%]). According to published work on the cost of adverse drug events, the total cost avoidance for the 33 preventable adverse drug events reported by pharmacists in this study was US$84,631 and the cost-benefit ratio was 1.2. One of the problems noted in the economic analysis was the difficulty in assigning more specific cost figures to each of the interventions that was estimated to result in more than US$1000 in cost savings. Conclusions: Pharmacists can play an important role in preventing medication-related problems (particularly adverse drug events), and the interventions they perform are cost-beneficial.

PMID: 20502172;Abstract:

The objective of this article is to describe adverse drug events related to the liver and gastrointestinal tract in critically ill patients. PubMed and other resources were used to identify information related to drug-induced acute liver failure, gastrointestinal hypomotility, constipation, diarrhea, gastrointestinal bleeding, and pancreatitis in critically ill patients. This information was reviewed, and data regarding pathophysiology, common drug causes, and guidelines for prevention and management were collected and summarized. In cases in which data in critically ill patients were unavailable, data were extrapolated from other patient populations. Drug-induced acute liver failure can be caused by many drugs routinely used in the intensive care unit and may be associated with significant morbidity and mortality. Drug-related hypomotility and constipation and drug-related diarrhea are reported with many drugs, and these are common adverse drug events in critically ill patients that can substantially complicate the care of these patients. Drug-induced gastrointestinal bleeding and drug-induced pancreatitis occur less frequently, can range in disease severity, and can be associated with morbidity and mortality. Many drugs used in critically ill patients are associated with adverse drug events related to the liver and gastrointestinal tract. Critical care clinicians should be aware of common drug causes of drug-induced acute liver failure, gastrointestinal hypomotility, constipation, diarrhea, gastrointestinal bleeding, and pancreatitis, and should be familiar with the prevention and management of these diverse conditions. Copyright © 2010 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins.